Uh, oh! Many bandwidth meters aren’t accurate

If you’re like the majority of Americans with broadband Internet access, you’re living under a data cap. Hopefully, your provider gives you a way to measure it with some kind of meter, such as the one shown above. It’s from my Comcast account, and even though it includes the notation that “enforcement of the 250GB data consumption threshold is currently suspended”, the meter continues to keep watch on how much data I use.

But apparently, your meter may not be giving you information that’s trustworthy. GigaOM reports that many broadband meters are inaccurate, which means you could cruise past a data cap without knowing it. You could face overage charges or, depending on your ISP’s policies, suspension of your account.

GigaOM reporter Stacy Higginbotham talked to Peter Sevcik, the president of NetForecast, a company that audits and certifies meters.[PDF] However, only one customer has received certification and opted to publish the report — Comcast, which serves much of the Houston area. Another customer has won certification but has not published the results. Five of NetForecast’s clients have come up with inaccurate meters and thus could not be certified. Sevcik wouldn’t name them.

However, the inaccuracy often favors the customer. From GigaOM:

“They are wrong by missing numbers by one way or another — sometimes it’s over-reporting, but more frequently the error is under-reporting,” he said. Under-reporting should be a relief to those facing overage charges or service termination for going over their meters, but if the meters aren’t counting the data properly, it is still a problem.

Also disturbing is the attitude that Sevcik has encountered at some clients with malfunctioning meters. “There’s a general sense by some people, ‘Eh, we under report so we give them a free pass, so why worry about that?’” Sevcik says. “I think one does need to worry because it ruins the overall veracity of the meter. It derails trust in the meter.”

Although Sevcik won’t call out clients with inaccurate meters, NetForecast’s site lists its clients, so you can figure out who’s got meters that don’t report usage truthfully:

Sevcik wouldn’t name those clients, but his website lists Time Warner Cable, Cox, Comcast, AT&T, Bell Canada, Verizon and France Telecom as customers. Time Warner Cable and Cox have both confirmed to me that they have used NetForecast to certify their meters. While Verizon doesn’t have a broadband cap or a meter, Verizon emailed to confirm that it is not using NetForcesat on the wireline side. AT&T’s spokesman says it has a team of engineers that certifies the accuracy of its meters but that it hasn’t worked with NetForecast to certify its wireline meters. Sevcik clarified that the seven clients he’s speaking of are all U.S.-based and all are testing wireline meters.

The GigaOM report focuses on wireline broadband for home users, but meters are even more important for mobile broadband, which has tiers as well as data caps. How accurate are those meters?

Depending on your carrier and phone platform, there may be a way to check your data usage in multiple ways. For example, AT&T offers an app that shows you data consumption within the current billing period. And if you have an iPhone, you can see in the settings (Settings > General > Usage > Cellular usage) how much data you’ve consumed since your last reset. If you hit reset on the first day of each billing cycle, you can get a second opinion on how much data you’ve used.